1. Field of the Invention
This invention relates to a metering device of a single lens reflex camera, and more particularly to a metering device of a single lens reflex camera in which part of a light beam to pass from the picture-taking lens to a film surface is reflected, for example, by a sub-mirror provided rearwardly of a quick return mirror or by the film surface itself, whereby this light is metered.
2. Description of the Prior Art
As the metering device in a single lens reflex camera, there is known one in which metering is accomplished by a set of a large-diametered condenser lens 3 disposed on the lower surface of a mirror box 1 and substantially facing the center of a film 2 and a light receiving element 4 installed on the condensing surface of the condenser lens, as shown in FIG. 1 of the accompanying drawings. A disadvantage inherent to such device is that the set of the condenser lens 3 and the light receiving element 4 has a considerably great thickness in the direction of the optical axis of the lens 3 and it occupies the entire space from the upper surface of the mirror box 1 to the bottom plate of the camera and therefore, the various mechanisms originally existing in that space must be moved into other space and this gives rise to difficulties in designing of the camera or that some cameras have a mechanism such as a diaphragm-interlocked lever which can hardly be moved from that space into other space and such cameras cannot at all adopt said device.